import CodeBlock from "@theme/CodeBlock";
import Tabs from "@theme/Tabs";
import TabItem from "@theme/TabItem";

# @farmfe/js-plugin-postcss
Support `postcss` for Farm.

## Installation

<Tabs>
  <TabItem value="npm" label="npm">
    <CodeBlock>npm install @farmfe/js-plugin-postcss postcss</CodeBlock>
  </TabItem>
  <TabItem value="yarn" label="yarn">
    <CodeBlock>yarn add @farmfe/js-plugin-postcss postcss</CodeBlock>
  </TabItem>
  <TabItem value="pnpm" label="pnpm">
    <CodeBlock>pnpm add @farmfe/js-plugin-postcss postcss</CodeBlock>
  </TabItem>
</Tabs>

## Usage
```ts {2,6}
import { UserConfig } from '@farmfe/core';
import farmJsPluginPostcss from '@farmfe/js-plugin-postcss';

const config: UserConfig = {
  plugins: [
    farmJsPluginPostcss({ /* options */ })
  ]
}
```

## Options
```ts
export type PostcssPluginOptions = {
  /**
   * @default undefined
   * postcss-load-config options. path default to farm.config.js root.
   */
  postcssLoadConfig?: {
    ctx?: postcssLoadConfig.ConfigContext;
    path?: string;
    options?: Parameters<typeof postcssLoadConfig>[2];
  };
  filters?: {
    resolvedPaths?: string[];
    moduleTypes?: string[];
  };
  implementation?: string;
};

```

### postcssLoadConfig
Farm uses `postcss-load-config` to load `postcss` config, so you can use `postcss-load-config`'s options. Refer to [postcss-load-config](https://github.com/postcss/postcss-load-config).

Example:
```ts
import path from 'node:path';
import { UserConfig } from '@farmfe/core';
import farmJsPluginPostcss from '@farmfe/js-plugin-postcss';

const config: UserConfig = {
  plugins: [
    farmJsPluginPostcss({
      postcssLoadConfig: {
        // load config from client/postcss.config.js
        path: path.join(process.cwd(), 'client')
      }
    })
  ]
}

export default config;
```

### filters
Which files should be processed by `postcss`. default to `{ moduleTypes: ['css'] }`.

* `resolvedPaths`: Only files under these paths will be processed. Support regex.
* `moduleTypes`: Only files with these module types will be processed. note that less/sass files should be processed by `@farmfe/js-plugin-less`/`@farmfe/plugin-sass` first. 

`resolvedPaths` and `moduleTypes` are unioned, which means files match any of them will be processed.

Example:
```ts
import { UserConfig } from '@farmfe/core';
import farmJsPluginPostcss from '@farmfe/js-plugin-postcss';

const config: UserConfig = {
  plugins: [
    farmJsPluginPostcss({
      filters: {
        // all files end with .custom-css will be processed
        resolvedPaths: ['\\.custom-css$'],
        moduleTypes: ['css']
      }
    })
  ]
}

export default config;
```

### implementation
`implementation` package name of `postcss`. Default to `postcss`.